The present invention relates to an interface apparatus and method for interfacing between a selector and a plurality of vocoders in a mobile communication system, and more particularly to an interface apparatus and method for interfacing a plurality of vocoding modules for coding/decoding a voice signal with a selector in a code division multiple access (CDMA) mobile communication system.
Generally, a mobile communication system, such as a cellular phone, portable phone, etc., is broadly divided into a radio base station, a mobile telephone terminal, and a mobile telephone exchange. A selector and a vocoder included therein code and decode voice data between the radio base station, to which a plurality of terminals are subscribed, and the exchange, and select a corresponding line by analyzing the voice data. The type of interface between the selector and the vocoder can be classified as follows:
First, there is serial access. The serial access has an advantage in that the burden of processing interrupts at a main processor of the selector is reduced. However, the relationship between the selector and the vocoder is of the form of a master and slave, and it therefore is necessary to design hardware connecting vocoding modules with one another and software or firmware corresponding thereto. PA1 Second, there is parallel access. In parallel access, the main processor of one selector is connected, one by one, to the vocoding module. Therefore, although the whole construction is connected in parallel, it is difficult to design an efficient select board.
A technique for adaptive synchronization arrangement for a CDMA cellular radio-telephone system is disclosed in U.S. Pat. No. 5,195,091. This patent describes mutual transmission, including a destination interface identification board address and a port address in a transmission frame. However, interfacing using a buffer is not described.